Leaves: Those of branches and stems alike, distant to closely-spaced (Crum and Anderson et al. 1981), overlapping or flat against the stem when dry, upright or spreading a little when damp, in 3 vertical rows along the stem (FNA 2014) with those below more remote and spreading, those above more crowded, upright and overlapping (Flowers 1973), strongly folded longitudinally, curving from base to tip along the keel, 2-8 mm in length, egg-shaped, sometimes tending to oblong, seldom approaching circular, tapering to the acute to nearly obtuse and sometimes curved apex; base extending down the stem; leaf edges sometimes bent back and downward widely below on one side (FNA 2014) or sometimes both sides (Flowers 1973); costa absent or scarcely developed (FNA 2014).

Leaf Cells: Medical cells of the lamina long and slender, tapering at the ends, to long and narrowly diamond-shaped; alar cells oblong, swollen, the walls flaccid (FNA 2014).

Range Comments

North American Range

Canada: YT, BC to AB, ON to NL and NS; USA: AK, states west of (to the coast) and including MT to NM, also SD, MN, WI and IL, MI, OH, e and ne to the coast (FNA 2014). Known in Montana from Carbon, Cascade, Flathead, Gallatin, Glacier, Lake, Lincoln, Mineral, Missoula, Ravalli, and Sanders Counties (Elliott and Pipp 2016).

(Observations spanning multiple months or years are excluded from time charts)

Habitat

Affixed to stones, small dead branches, tree and shrub roots and submerged in running water (Crum and Anderson et al. 1981), also pools, swamps, flat area that flood; occurring from lowlands to about 10,826 feet elevation (FNA 2014).

Lawton, E. 1971. Keys for the Identification of the Mosses on the Pacific Northwest. Reprinted from 'Moss Flora of the Pacific Northwest'. Published as Supplement No. 2 of the Journal of the Hattori Botanical Laboratory. Nichinan, Miyazaki, Japan. 66 pp.